This invention generally relates to portable toilets and more particularly relates to a portable toilet which carries its own power supply for operating the flush assembly. Portable toilets of the general type to which this invention relates are typically provided with either a manually or electrically operated pump for pumping flush water from a water storage tank into the toilet bowl. It is the latter variety to which this invention particularly relates.
U.S. Pat. No. 4,185,337, assigned to the assignee of the present application, shows a portable toilet with an electrically operated flush assembly. The flush assembly illustrated in this patent requires an external source of power and involves a continuous flush which has limitations from the standpoint of flush water efficiency. U.S. Pat. No. 4,926,508, also assigned to the assignee of the present application, shows a portable toilet with a power assisted flush assembly which is operated off of batteries carried by the toilet itself. This battery operated assembly is flushed by depressing a hollow cap member, known as a palm button because it is intended to be depressed with the palm of a hand, which is mechanically connected to a valve that opens in response to depression of the palm button and which cause the pumping of flush water.
One of the hazards involved in using a portable toilet is the possibility of flush water being inadvertently spilled when the toilet is not in use, such as during transportation. Unless the flush water is blocked from flowing into the bowl, the flush water will inevitably leak into the bowl while the toilet is being transported. To prevent this from happening, a spring biased check valve is incorporated into the flow path between the pump and the toilet bowl. In a toilet with a manually operated flush mechanism, such a restriction is not objectionable because the same large force necessary to operate the manual flush assembly is sufficient to open the check valve and achieve good flushing of the toilet. In a battery operated assembly, such a check valve is not used. Rather, a valve mechanism which is manually opened during initiation of a flush by the same actuator movement that closes the battery switch to power the flushing operation is used. This reduces the demands on the battery. In this manner, the electrically operated assembly can be made to use as little power as possible during flushing and thereby decrease the frequency with which the batteries must be changed. This construction, however, increases the cost of the battery operated flush assembly and further requires that numerous additional or alterative production steps be used when constructing the toilet with the battery operated flush assembly as opposed to the manually operable flush assembly.
Another limitation of the electrically or battery operable flush assembly is that changing the batteries associated with the portable toilet can be a complicated event that may require specific tools or numerous procedures. Once the, batteries have been replaced, it is important to ensure that when remounted within the flush assembly, the batteries are easily isolated by the establishment of a fluid-tight seal.
In view of the above and other limitations, a principle object of this invention is to provide an improved battery operated flush assembly for portable toilets which does not require manual opening of a closure associated with the discharging of flush water.
Another object of this invention is to provide a battery operated flush assembly which has a simplified construction that readily permits in-the-field replacement of the batteries and the reestablishment of a fluid-tight seal around the batteries.
A further object of this invention is to provide an improved battery flush assembly adapted for use with a check valve located in-line between the pump and the discharge nozzle of the portable toilet. The battery operated flush assembly of this invention does not require a manual closure to ensure that flush water does not leak into the bowl of the toilet.